This invention relates to the mounting of sensor windows used to protect sensors, and, more particularly, to a compliant mounting assembly that permits the mounting and window to be heated to elevated temperature without loss of mounting and protective integrity.
Various types of optical, electro-optical, infrared, acoustic, and radar sensors are used in missiles, aircraft, and other applications to sense the environment and especially to search for targets. The sensor itself is usually rather delicate and must be protected from aerodynamic forces, dirt, heat, and other external agents that could damage it. A protective sensor window that is transparent to the energy sensed by the sensor is placed over the sensor to protect it. The sensor window is held in place by a window mounting assembly.
In one application, an infrared sensor is protected by a infrared-transparent ceramic window in the shape of a truncated dome that fits over the sensor and is held in place in a metallic mounting. In conventional practice, an adhesive is used to bond the protective window to the mounting assembly. However, in some cases the sensor system is to be used in an aerodynamic environment where it may be heated to temperatures as high as 1200.degree. F. At such temperatures, conventional adhesives soften and are incapable of holding the protective window in place. Moreover, the differences in thermal expansion coefficients between the ceramic window and the metallic mounting may cause the window to become loose in the mounting so that hot gas could penetrate to the sensor and damage it. Tests using such a conventional approach have led to mounting-related failures.
There is a need for an improved sensor window assembly for a wide variety of sensor systems. The sensor window assembly should withstand elevated temperatures without loss of mounting integrity and protective function. The present invention fulfills this need, and further provides related advantages.